According to Noam Chomsky, linguistic theory should concern itself primarily with the investigation of a speaker's competence.

[…] if Eben comes to me with that there hankychy and slips a big wodge of hard Hamsterdam ’bacco and a square bottle o’ stuff as hasn’t paid dooty into my hands in the dark some night, what am I to do?

I cannot convey to you the sheer and surreal scale of everything: the towering ship, the ropes, the ties, the anchor, the pier, the vast lapis lazuli dome of the sky.

Thou that doest liue in later times, must wage / Thy workes for wealth, and life for gold engage.